Chibikko Tenshi

A story of the growth of an apprentice angel who came to the human world. The prototype of Mahou Tsukai Sally a masterpiece of girls' manga drawn by Mitsuteru Yokoyama, has been published in book form for the first time after half a century!
Two angels, Chiruru and Maruru, who do not know the right and wrong of the world, are sent to earth by the emperor of heaven to learn the right and wrong of things. What is the human world they see? ......
(Source : Public Brain, translated)